The generation of musical tones electronically, either by analog or digital circuits, is well known. In attempting to duplicate the sounds of conventional musical instruments it may be desirable to superimpose sounds which can only be characterized as "noise" onto the musical tones. Such added noise may be introduced to simulate the air noise, hiss, or breathiness characteristic of wind-operated instruments, such as the organ pipes of a conventional organ, or other types of wind instruments. In prior art digital type organs tones have been created imitative to noisy wind-blown organ pipes, by using a frequency modulation technique. This has been accomplished by adding or subtracting a fixed constant to the frequency number used to address the tone data. Alternatively, the noise has been added to the reference voltage of the analog output signal from the digital-to-analog converter to produce an amplitude modulated noise. Noiselike tones have been created in digital tone generators by the type which calculate musical waveshapes by computation with an algorithm that uses sets of harmonic coefficients. However, the resulting tonal effect is not easily controlled. If the harmonic coefficients are varied in a random fashion, noise having a very wide spectrum is produced and has the effect of substantially obliterating the basic musical tone being generated.